I think it’s a great comparison. You can punish someone without providing a reason, and so the poster just thinks other people are arseholes. You did it just because you can. You might think there’s no point arguing back, but the person who wrote the comment obviously thought it was a good point.

No, you should reply and explain why the advice is dangerous. A comment might be downvoted for all sorts of reasons and so it doesn’t send a clear message. Downvoting is like grounding your kids just because you are angry, without explaining what they did wrong. They will just conclude you are an arsehole that will punish them whenever you fancy. Which is exactly my opinion of redditors and why I stopped posting there.